Current-driven dynamics of domain-wall skyrmions in pinned channels

Abstract

Domain-wall skyrmions (DWSks) are topological spin textures confined within magnetic domain walls. These hybrid structures have recently attracted considerable interest due to their combination of advantageous features from both domain walls and skyrmions, including topological protection, low driving-current density, nanoscale size, and ease of read/write operations. Since DWSks are trapped within domain walls, theoretical studies suggest that their Hall motion can be substantially suppressed, enabling highly controllable one-dimensional propagation. However, in practice, when DWSks are driven by an electric current, the domain wall itself is also propelled into motion, which substantially increases the complexity of the dynamical behavior. In this study, we suppress domain wall motion by locally reducing the perpendicular magnetic anisotropy and systematically investigate the motion of DWSks within pinned domain walls. The proposed approach facilitates the design of densely arranged domain wall channels and supports the propagation of multiple DWSks within a single channel, consequently enhancing the integration density of DWSk-based devices. Our findings advance the understanding of DWSk dynamics and offer valuable insights for the development of future spintronic applications.